Multipolar Coupling in Hybrid Metal–Dielectric Metasurfaces

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• 作者：Rui Guo ; Evgenia Rusak ; Isabelle Staude ; Jason Dominguez ; Manuel Decker ; Carsten Rockstuhl ; Igal Brener ; Dragomir N. Neshev ; Yuri S. Kivshar
• 刊名：ACS Photonics
• 出版年：2016
• 出版时间：March 16, 2016
• 年：2016
• 卷：3
• 期：3
• 页码：349-353
• 全文大小：445K
• ISSN：2330-4022

文摘

We study functional hybrid metasurfaces consisting of metal–dielectric nanoantennas that direct light from an incident plane wave or from localized light sources into a preferential direction. The directionality is obtained by carefully balancing the multipolar contributions to the scattering response from the constituents of the metasurface. The hybrid nanoantennas are composed of a plasmonic gold nanorod acting as a feed element and a silicon nanodisk acting as a director element. In order to experimentally realize this design, we have developed a two-step electron-beam lithography process in combination with a precision alignment step. The optical response of the fabricated sample is measured and reveals distinct signatures of coupling between the plasmonic and the dielectric nanoantenna elements that ultimately leads to unidirectional radiation of light.